| The mold is the most important component which is called the "heart" of a continuous caster. During the casting process, temperature of mold copper plate especially the wide plate can easily be distributed non-uniformly, because of the high temperature, the backflow of molten steel and the edge effect of the cooling function. Then, the non-uniform temperature distribution will result in the local stress concentration of copper plate and have an adverse impact on the working life of mold. Therefore, it's an effective method to extend the working life of mold and improve the property of casting blank through promoting the heat sinking capacity of copper plate. For this purpose, temperature and thermal stress distribution of different copper plates were investigated by numerical simulation method in this work. And cooling system of the better copper plate was studied and modified based on the simulation results.Three-dimensional models of three copper plates were established by UG NX based on models which the plant provided. And the heat flux profile of copper plate hot surface was determined using an inverse method with temperatures measured in plant. This profile was then used for simulation to predict the temperature distribution and was adjusted until the temperatures calculated by the finite-element model at the thermocouple locations matched well with the measured ones.Based on the mathematical model and heat flux profile which determined by inverse method, thermal-stress coupled calculation of three different copper plates was conducted using ANSYS Workbench. According to the cross-section shape and arrangement of water slot, the three different copper plates were named copper plate ?, copper plate ? and copper plate ?. The calculation results showed that longitudinal temperature distribution trend of three copper plates was similar, but the temperature of copper plate ? was lower than that of copper plate ? and ?. At the same time, temperature of copper plate ? distributed more uniformly in the longitudinal direction, but it had a bad performance in the uniformity of transverse temperature distribution.In general, value of temperature and thermal-stress for copper plate ? is lower than that for copper plate ? and ?, therefore, further research for the cooling system of copper plate III was proceeded. To promote the cooling effect of copper plate ?, the influence of water slot's arrangement, width, depth and cooling water's velocity, temperature in the temperature distribution of copper plate was studied. And the calculation results indicated that the transverse temperature distributed more uniformly when a group of cooling water slots consisted of two side deep slots and five center shallow slots. And when the width of water slot was increased to 6 mm, temperature of bolts'top, water slots'top and copper plate hot surface could be reduced, meanwhile, the temperature of copper plate's central part would not be increased. Furthermore, when the depth of water slots were changed to 23 mm for two side deep water slots,18 mm for the central water slot and two water slots on the right side of the center, and 17 mm for the other two shallow water slots, the temperature of copper plate was lowered and the uniformity of temperature distribution was promoted as well. As for the cooling water, increase for velocity of cooling water could reduce the copper plate temperature, but the temperature drop range was not homogeneous when the velocity was increased by 1 m/s. And when the velocity was increased to 11 m/s, the cooling effect was more evident and it would not bring in the nonuniformity of temperature distribution. However, change of cooling water temperature had no significant effect in reducing copper plate temperature and promoting the uniformity of temperature distribution. |
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